Publish Official Typescript Typing's for all Data Models
It would be very easy to build and design for if there were official typing for all data endpoints. The data between all the different API's for the same data isn't consistent, and with event sub, since it no longer relies on the underlying Helix endpoint, that data can now be different too. This will also mitigate typos on the docs which causes huge headaches when trying to code for API responses and the data not working, or missing fields. The typing can specify which fields are required and which are optional, so when designing your app, you can easily make those checks.
An example is the Extension transaction data. On the ext helper, you get a signed receipt, but on the API end point, you don't. So depending on where you get the data, you need to code for 2 different scenarios for the same exact data.
Typings are published on NPM to be imported into a project, so on the documentation, you would just include directions on how to import it. Usually they are PR'd into @types/project https://github.com/DefinitelyTyped/DefinitelyTyped. Once imported your IDE then just knows how the objects are structured, and what values to expect. The new docs for Eventsub break it down very well with objects, and sub objects. Its basically that, but published on NPM.
As someone who is not familiar with TypeScript, I was curious if there was something specific about this typing to include, like how to format or represent it in the docs. OR is this request simply referring to the fact that return values and types are not defined in the Extensions reference page like the API reference?